I don’t want to be served by disabled waiters, I feel more sorry for my teeth than for the dentist’s father, and the orchestra must play well. The seller must smile.
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The seller should not smile to you. He must give you reliable information on the goods/services, issue an order, accept payment, be polite and not hesitate, finally, to accept the defective goods under warranty or exchange the defective goods according to Article 25 of the Civil Code. No one is obliged to smile.